Ride height/reindexing project gone wrong.
 

I just finished a four jackstand, all wheels off the ground reindexing torsions bars, Neatrix bushing repalcement project on my 78SC. I had my front bar caps in the center position, and my rear plates were at 32 degrees (I used the calculator: 2650 lbs, 24.1 mm bars).

Problem 1: I noticed unequal tosion bar penetration. My passenger bar is approx. 3/8" in from the end of the tube. Driver side is flush. I checked everything, it looks perfect on both sides.

Problem 2: My rear track is now uneven by quite a bit maybe 1/2". My driver side tire is almost flush with the fender. Passenegr side, the one with less penetration, looks about right. ???

WTF! I really took my time with this over the course of 3 days.

Unfortunately my year of 911 ownership has been full of projects like this. Something always went wrong. It's not the car, I just don't seem to have any mechanical talent.

Just venting sorry.

Ulrich

Welcome to the DIY lowering job club, Ulrich.
I spent days doing my lowering job a couple of years ago. Even with the help here and in the 101 Projects book it still was a PIA for me.

The best thing to do now is to get it aligned by a pro shop that deals with these cars or at least high end vehicles.
Maybe post pictures of what you mean and we can help diagnose.

BTW-The wheels look great on my SC. I can't wait to get the engine and trans installed in a few weeks.

Ulrich,

Did you put any anti-sieze compound on the torsion bar splines? A 3/8" offset is a lot for a trailing arm on one side ... but that wouldn't translate to 1/2" change in rear track! You may want to take off that side's cover and put anti-sieze on the inner splines of the trailing arm and whack with a large mallet with a piece of 2 x 6 over the arm cap.

Have you driven the car, yet? If not, the do so before making any judgements about appearance. The car will do some settling after driving a few miles. I have serious doubts that the rear track could shift by any more than 1/8" - 1/4" ... after bushings have settled and trailing arms found their natural center between the bushings.

You just can't count on the static settings, like centering the adjusters on the front caps. That's just a starting point, like adjusting ignition points on an early car. After you drive it as Warren says, you need to weigh it at all four wheels.

As Wayne says, maybe just have it done at this point. The alignment shops just don't charge that much. You've done all the hard work.

Also, don't expect these cars to be symmetrical. They're close, but not perfect right from the factory. Certainly don't use the body as a reference for accurate alignment. Also, don't forget to measure the rocker panel for level when it's up on the jacks, and include the value in the calculation for the spring plate angle.

Thanks for the responses guys. My main problem right now is the uneven torsion bar penetration. I measured the torsion bars sticking out of the tube and they were equal. Whatever is wrong is in the spring plate or cover.

Ulrich

We need pics of that.

Ulrich; I had my first spring plate, tosion bar experience just last spring in my 71', I had them on and off a few times and due to rust particles and just really tight fitting splines, I had a slight off-set issue as well. Before I put the spring plates on I tapped the torsion bars in with a rubber mallet, I used a 1/2" drive with a rubber grip to ease the schock and to fit through the torsion bar access hole. Remember the torsion tube passes all the way through so if something is blocking or corroded your situation could happen. Make sure that the splines are well lubed and free of rust and pitting, on the bars and in the tube. If the spring plates and bushings go all the way on, your torsion bars will line up. Try to be patient, I don't learn if I don't do something wrong. It's only February, David

Did you grease the rod well before putting in back together?

btw I would never put anti-seize on them, they can be a bear to remove with just grease . . . the bushings stick etc . . .

Ian

I did. Tomorrow I am going to swap spring plates left to right. I know not to swap torsion bars.

Ulrich

LOL. They all go wrong the first time. Welcome to the club ;)

you have to watch if you put too much grease or anti grease at the end it some times builds an air pocket which keeps you from pushing it in all the way .the grease compresses air at the end of the torshion bar which traps air unless you remove will not release ....but that only my 2 cents

I had a nasty time taking out one of my torsion bars from the tube splines this past summer when I was reindexing. Once out, I cleaned it up and tried putting it back in. It just would not fit. I tried the t-bar from the other side just to see if it would fit and it did just fine. That made me think that the t-bar that did not fit was a little larger than the other one...so I filed it down just a wee bit until it fit snuggly.

I did'nt really want to do this but I could not see any other way to fit the bar in other than maybe to freeze it and then try but I am glad I filed it because I had to take the bar out a couple of times to get the ride height the way I wanted it.

When you tighten the bolts on the spring plate cover they suck everything in. Its tight if you used new bushings and you have to take your time working around the cover to get everything to tighten square.

what size rims due you have in the rear. I would think if they are stock size they would be one half inch in from the lip of the fenders. I think I recall that you can knock the torsion bars all the way thru on the torsion bar tubes on the car. but if you tighten the covers all the way they should be perfect. they butt up next to one another in the middle. I would try taking the one out that is sticking out to far. Look at the cover to the spring plate does it look crooked or not tightened evenlly

Ok, partially solved mystery. I get only partial torsion bar penetration in one swing plate and my track has widened on the other side.

It seems that one side has a damaged swing plate or torsion bar and when it can't penetrate any further (assume the splines are damaged) it pushes the other torsion bar out. I tried it again today, and sure enought when I wa done with one side the torsion bar on the opposite side hadcome out about 3/8". I assume this had a subtle effect on the trailing arm position which would explain the change in track width.

Now, to get a new "used" spring plate ot torsion bar (24.1mm)?

Ulrich

This can be a very difficult project, particularly if you haven't done it before. I think the last time I had this done, I just took it to my buddy at the alignment shop (Alex Wong), and told him to lower it. Cost is about $600. It can be easy, or it can be SUPER difficult depending upon the condition of the components. I remember Alex mentioning once that he had to cut the torsion bar end off to get the spring plate cover off.

Anyways, with all of the components off, you need to drive the car, and then see how it sits. Then put it on corner balance scales and check the left/right distribution. Make no mistake - this is not a super-easy project - it takes patience, and understanding that you will go back and adjust everything quite a few times.

If you have patience, then the results will be wonderful!

-Wayne

Inspect both the spring plate and the torsion bar (it's usually either dirt in the spring plate, or boogered threads on the torsion bar). You may be able to use a small reamer to clean the threads up, if there is only very slight damage from dirt or sand...

-Wayne

Thanks Wayne. I had actually done it before but the partial spline penetration one one side and track widening on the other threw me for a loop this time around.

Ulrich

Do you guys remove the toe adjuster bolt when you separate the spring plate from the trailing arm? I usually don't. Any thoughts.

Ulrich

When I did it I removed the spring plate from everything. I think you would run into binding probems if you didn't remove the whole thing.

Ulrich

We are talking rear torsion bars, right?

In one of your posts you assume that pushing one torsion bar in pushes the other out. But I'm pretty sure these bar ends don't touch. There is a big solid steel slug welded into the center of the torsion tube, with a hole in the center which is splined at each end. I've yet to cut open a tube to inspect one, but it has to be designed so the bars individually bottom. I suppose that with lots of grease maybe you could create a hydraulic action if the hole was drilled through before the splines were cut, but that would be a soft action.

As to what you remove, if you can leave some stuff attached and still get the plate off the bar so you can adjust the plate and bar, why not. You have the two piece plate, right? So you can separate it at the height adjusters and not the camber/toe adjusters?

I pulled everything apart last summer when I canged the T bars and bushings because it seemed the thing to do, but by paying careful attention to angles I didn't have to reset the bars after reassembly. A little ride height adjustment and the corner balance came right in on the scales.

Walt Fricke

Walt,
Thanks for the response. I guess my mistery remains. After my last reindexing, I had one torsion bar that only penetrated the spring plate partially while the other side was fine. After dropping the car I noticed that the track on the opposite side, from the partial penetration, was now wider. I am replacing the torsion bar and spring plates on one side, let's see what happens.

Ulrich

Regarding the uneven ride height, did you center the spring plates before you measured the angle and resinstalled? If not, this could be part of the problem. Also, when installing the rear bars, I like to get the bar in the spring plate splines, making full contact, before getting the bars in the chassis splines.

Jon,
It's not the ride height that's uneven, it's the track width. All of a sudden my driver side rear wheel sticks out further than the passenger side. I am trying to determine how that's related to the uneven spline penetration.

Ulrich

Could it be that the camber adjustment is as far "positive" as it will go? This would give the appearance of the track being off.

Torsion bars....
 

[QUOTE]Originally posted by Walt Fricke
[B]Ulrich

We are talking rear torsion bars, right?

In one of your posts you assume that pushing one torsion bar in pushes the other out. But I'm pretty sure these bar ends don't touch. There is a big solid steel slug welded into the center of the torsion tube, with a hole in the center which is splined at each end.

Walt / Ulrich,
The inner ends of the torsion bars for '78SC come in contact. If you push one torsion bar too far inside, the other torsion bar on the other side will move out. You could actually disengage one TB by using the other TB to push it out.

Test the TB covers for splines fitment with TB out in the car. Measure how far the TB slides into the cover (with splines) for both TB.

TD

Re: Torsion bars....
 

[QUOTE]Originally posted by boyt911sc
[B] TD,
Yes, shining a flashlight through the tube I don't see any obstruction in the center. This would indeed explain the symptons I found. Thanks for this information.

Ulrich

If your torsion bars are installed and the covers are tightened down and they look the same on left and right maybe it is something else. Look at your camber and toe settings. I doubt they could make that much of a differrence though.

Picture is what we need.

If one bar was sticking out that far, I doubt the cup would butt against the threaded bosses.

Here a picture of the spring plate and cover on my car. It seems to me that the spring plate cannot move out if the cover bolts are tightened down. However, if the splines inside the torsion tube allow the torsion bar to travel farther than the correct position, it seems that the spring plate could move in a bit towards the torsion tube. However, even if it moved enouph to touch and displace the other torsion bar on the other side of the car, I dont see how it could move the spring plate on the other side out more than the maximum that the spring plate cover will allow - that cover is bolted down!

Could it be that the right rear spring plate is positioning itself too far in towards the torsion tube because the inner splines in the torion tube on the right side are broken and allow it to travel too far in?

If that happens, could the right rear wheel appear to be further in than the left? Just some thoughts.

Here's the pic.

http://forums.pelicanparts.com/uploa...1170728454.jpg

Tim,
Thanks very much fot taking the trouble. Actually, my spring plate tubes have no covers on them. I had to pop them off way back because my torsion bars were stuck in the tubes and I had to tap them out. This is how I am able to see the uneven bar penetration left to right. As Boyt pointed out earlier the tubes do touch each other on the 78, so if one bar is obstructed it could theoretically push the other one out as you are tightening the covers. I'll try again this weekend with another springplate. This time I'll disconnect the droplinks to take the swaybar out of the equation, which I didn't do last time. Hopefully the unequal reat track was just a badly aligned trailing arm.

Ulrich

Well here is the photo evidence. The reason I have no caps on the tubes is that I had to tap the torsion bars out of the spring plates the first time I did this a year ago.

The first pic is the driver's side bar which was flush with the end of tube until I started on the other side and then gradually was pushed out as I tightened the cover plate on the passenger side.

Prior to install I measured the amount that the bars protruded out of the hole (equal) and both bars inserted without problems into the spring plates manually (so no spline problem). I can't see any problem in the torsion bar tube with my flash light.

Is it just the missing spring plate caps? Thanks in advance for your input.
http://forums.pelicanparts.com/uploa...1170788396.jpg http://forums.pelicanparts.com/uploa...1170788408.jpg

The end caps sit flush with the end of the tube. Are these new/used T-bars? If so, could they be G-50 bars? I know G-50 bars are a different size, just not sure if they are longer.

Aha - now I see.

First off, this just plain can't affect the track at the rear of your car. Track is the distance between the tire centerlines measured from the contact patch on the ground. The outer holder plates (I won't call them covers to avoid confusion) that the four bolts secure look (pictures aren't totally clear on this) to be where they belong - drawn up tight against the posts that extend out from the body. That means the spring plate is where it belongs. Whatever it is about how the tire sits in the wheel well that led you to believe your track changed is due to something else.

And of course you need to get that one bar back into its holder, and to get the other bar fully seated in its. If you can't drive the left side bar in (which would also drive the right bar out to where it belongs, I have learned from this useful discussion), something is obviously wrong with the splines in the right side holder (or, I suppose, on the end of the right side bar itself). Whatever is wrong you ought to be able to fix by cleaning everything, inspecting, feeliing with your fingers, running scrapers through, using little files, and otherwise finding the small burr or bit of rust that must have caused this and dealing with it and applying a little bit of lubrication. My bet is that this is inside the holder.

I've not had to pull one of the circular covers off of a holder. How does one reinstall that? Will it just pop back in?

Walt Fricke

Ulrich,

I'm glad we finally have the visual situation at hand!

That torsion bar is sticking out far more than 3/8" past its' normal location ... taking into account the cover normally peened into the trailing arm socket! However, it would seem to be a fairly straightforward fix to me -- even if time-consuming. I again reiterate that anti-sieze compound needs to be applied to the torsion bar splines to reduce friction while putting things back together and to prevent corrosion in the future.

I think you should tack-weld the covers back on the trailing arms in at least three places ... both to prevent torsion bar 'travel' and to protect from the elements in the future!

Jon, Warren and Walt,
Thanks for the responses. As I mentioned, I test fitted each torsion bar, well lubed, into the corresponding spring plate manually outside of the car in order to eliminate the splines as a possible culprit. I don't feel comfortable just hammering it back in so I have ordered a used springplate with cover intact from DC Automtive. I will install it on one side first and then do the other and report on the results. Hopefully it is just the fact that the torsion bar that goes in first has no stop with the cap missing.

FYI, I pried the caps off when I found that my torsion bars were stuck in the plates about a year ago. This way I could tap them out. I have plastic caps over the ends to protect th bars from dirt.

Ulrich

Ulrich

Plastic caps should keep the dirt and mositure out, but what about Warren's advice?

As you have shown us, the caps are all (other than some friction) that keep the bars where they belong. I suppose that doesn't worry you if you drove for several years with plastic caps. But something to think about when you get things sorted out. And have well lubricated/anti-seized bars that slide in and out easily.

Walt

Walt,
Now that I understand how important these caps are I will definitely get this corrected. Thanks to all who responded.

Ulrich

So what happens if you take a dead-blow hammer and tap the extending bar back in? I would think it would drive the other out and self-center the pair. And I doubt the bar protrusion has anything to do with your track difference.

By the way, how duid you measure the track to determine it's off?